Installation for venting the crankcase of an internal combustion engine

ABSTRACT

An installation for venting the crankcase of an internal combustion engine in which a vent line that terminates in the crankcase, is positively closed off with respect to the atmosphere when the throttle valve in the exhaust gas line is closed, for example, during engine braking.

United States Patent Buhl [4 1 May 16, 1972 INSTALLATION FOR VENTING THE CRANKCASE OF AN INTERNAL COMBUSTION ENGINE Hans-Wilhelm Buhl, Stuttgart-l, Germany Assignee: DalmlehBenz Aktiengesellschaft Filed: Apr. 23, 1970 Appl. No.: 31,236

Inventor:

Foreign Application Priority Data Apr. 25, 1969 Germany.....; ..P 19 21 068.5

11.8. CI. ..123/1 19 B, 123/97 B Int. Cl ..F02f 9/02, F02m 25/06 FieldoISearch ..123/119B,4l.86,97B

References Cited UNITED STATES PATENTS 8/1965 Scholtyssek ..123/97 R 3,500,806 3/1970 Sarto et al. ..123/97 B X 2,064,720 12/ 1936 Balogh 3,157,169 11/1964 'Drysda1e..

3,482,562 12/1969 Ranft ..123/97 B X FOREIGN PATENTS OR APPLICATIONS 1,476,036 3/1969 Germany ..123/1 19 B 431,702 7/1926 Germany ..123/1 19 B Primary Examiner-Mark M. Newman Assistant Examiner-R. B. Rothman Attorney-Craig, Antonelli and Hill 57 ABSTRACT An installation for venting the crankcase of an internal combustion engine in which a vent line that terminates in the crankcase, is positively closed ofi with respect to the atmosphere when the throttle valve in the exhaust gas line is closed, for example, during engine braking.

21 Claims, 5 Drawing Figures PATENTEnm 16 I972 3.662.723

HANS WILHELM BUHL BY ATTORNEYS INSTALLATION FOR VENTING THE CRANKCASE OF AN INTERNAL COMBUSTION ENGINE The present invention relates to an installation for the venting of the crankcase of an internal combustion engine.

The aim underlying the present invention essentially resides in creating an installation of the aforementioned type by means of which is avoided that the vent gases are able to reach the atmosphere during a pushing operation with a closed exhaust gas line, ,i.e., during an operation when the vehicle as prime-mover pushes the'engine. As solution to the underlying problems, a closure valve is provided according to the present invention in the vent line for the vent gases which, with a closed throttle valve in the exhaust gas line, positively and forcibly closes the vent line with respect to the atmosphere.

In order to avoid that an excessive vacuum occurs in the crankcasing, according to a further feature of the present invention, the crankcase and a connecting pipe in communication with the atmosphere may be connected in parallel with the vent line whereby a pressure control valve may be arranged in the connecting pipe which opens up the connecting pipe in case of non-permissive pressures in the crankcase.

The volume of the vent line suffices during short periods of pushing operation in order to be able to accommodate the vent gases. However, it may be appropriate in particular for commercial types of vehicles that an air tank is connected to the vent line between the crankcase and the closure valve.

According to a still further feature of the present invention, the closure valve and air tank are arranged in the air suction line whereby the closure valve is located upstream of the air tank effective as muffleror noise damper.

For the purpose of increasing the suction effect a suctiontype vent pump may be provided in the vent line.

The vent line may terminate in the suction air line upstream of the suction air filter. If, however. an air filter is provided in the connecting pipe for the atmospheric air, the vent line may also terminate in the suction air line downstream of the suction or intake air filter.

Accordingly, it is an object of the present invention to provide an installation for venting the crankcase of an internal combustion engine which avoids by simple means the afore mentioned shortcomings and drawbacks encountered in the prior art.

Another object of the present invention resides in an installation for venting the crankcase of an internal combustion engine which prevents the venting gases to reach the atmosphere when the exhaust gas line is closed.

A further object of the present invention resides in an installation for venting the crankcase of an internal combustion engine which is safe and reliable in operation, yet is simple in construction.

These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, two embodiments in accordance with the present invention, and wherein:

FIG. 1 is a schematic view of a first embodiment of an installation for venting the crankcase of an internal combustion engine without suction pump;

FIG. 2 is a schematic view of the installation according to FIG. 1 with the closure valve thereof in a different position;

FIG. 3 is a schematic view of a modified embodiment of. a. second installation for venting the crankcase of an internal combustion engine which is provided with a suction pump;

FIG. 4 is a partial schematic view illustrating certain details of the installation according to FIG. 3 with the closure valve in a different position; and

FIG. 5 is a schematic view of a modified embodiment of a third installation for venting the crankcase of an internal combustion engine which has the air filter located upstream of the vent line.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate like parts, and more particularly to FIG. 1, reference numeral 10 designates in this Figure the crankcase, reference numeral 1 I the cylinder head, reference numeral 12 the exhaust gas line, and reference numeral 13 the suction line while reference numeral 14 generally designates the vent line of an internal combustion engine terminating in the crankcase 10 thereof. An air filter 15 and upstream thereof an air tank or reservoir 16 are arranged in the suction line 13 whereby the discharge end 14a of the vent line 14 terminates in the suctionline 13 between the filter 15 and the tank 16. A throttle valve 17 is arranged in the suction line 13 upstream of the air tank 16; the throttle valve 17 is operatively connected or coupled by way of a linkage 18 with a throttle valve 19 for closing the exhaust gas line 12. The linkage 18 is in operative connectionby way of an actuating connection schematically indicat'edby 20 with a brake lever (not shown) in the driver cab of the motor vehicle driven by the internal combustion engine.

A pipe connection or stub 21 for atmospheric air is connected with the vent line 14 in parallel to the crankcase 10. A pressure limit valve 22 of conventional construction is arranged in the pipe connection or stub 21. It is avoided by this arrangement that the vacuum in crankcase 10 may assume non-pennissive values. I

OPERATION The operation of the installation of FIGS. 1 and 2 is as follows.

In the illustrated open position of the throttle valves 17 and 19 (FIG. 1), the vent gases from the crankcase 10 reach the cylinder head or the working cylinders by way of the lines 14 r and 13 during load-, idling-, and pushing-operating conditions.

The venting, i.e., the drawing-01f of the gases out of the crankcase 10 takes place during the aforementioned operating conditions of the engine as a result of the suction effect of the cylinders. p

The venting conditions during a pushing operation with a closed throttle valve 19, i.e., when the engine isbeing pushed, are visible from FIG. 2. In this position of the throttle valve 19 also the throttle valve 17 is forcibly brought into its closing position by way of the linkage 18 so that the communicating line system l3, 14 is closed with respect to'the atmosphere. The vent gases forced out of the crankcase 10 by reason of the pressure build-up in the line 12 collect in the air tank 16 by way'of the vent line 14. The pipe connection or'stub 21 is thereby closed by means of the valve 22. The crankcase gases therefore have no possibility to escape into the atmosphere. If the engine braking is terminated by opening the throttle valve 19 in the exhaust gas line 12, the removal of the crankcase gases takes place by the suction effect of the working cylinders.

The installation schematically illustrated in FIGS. 3 and 4 differs from the arrangement of FIGS. 1 and 2 only in that a suction-type vent pump 123 is provided in the vent line 114 between crankcase and the closure valve generally designated by reference numeral 117 and in that the air tank tion with a brake lever in the driver cab by means of an actuating transmission 120. A pipe connection or stub 1 21 for the atmospheric air terminates in the vent line 114 between crankcase 1 10 and closure valve 117. A pressure limit valve 122 for the vacuum of the crankcase 110 is arranged in the pipe con nection or stub 121. The outlet end 114a of the vent line 1 14 terminates in the air suction line 113 upstream of the air filter 115. The air tank 116 is connected by a tank line 116a with the closure valve 117 whereby the arrangement is made in such a manner that with a tumed-ofi engine brake, i.e., opened throttle valve 119, the, crankcase 110 is connected with the suction line 113 (FIG. 3) whereas in the closing position of throttle valve 119 it is connected with the air tank 1 16 (FIG. 4).

OPERATION The operation of the second embodiment illustrated in FIGS. 3 and 4 is as follows:

With a turned-01f engine brake, i.e., opened throttle valve 119 (FIG. 3), the crankcase gases sucked off by the pump 123 are fed to the working cylinders by the suction effect in the line 113. With an engaged engine brake, i.e., corresponding to the closing position of the throttle valve 119 in FIG. 4, the vent line 114 is closed off with respect to the atmosphere and is connected with the tank 116. Consequently, it is not possible that the exhaust gases can escape into the atmosphere during a pushing operation.

An excess pressure valve 124 may be arranged in the air tank 116 which opens up a communication 125 between the suction line 113 and the air tank 116 when exceeding a predetermined excess pressure. After turning ofi or disengagement of the engine brake, the crankcase 110 is again connected with the air suction line 113.

The installation schematically illustrated in FIG. 5 differs from the arrangement of FIGS. 1 and 2, only in that the air filter 215 is located upstream of the vent line 214 and in that another air filter 224 is provided on stub pipe 221. The reference numerals in this FIG. 5 correspond to the reference numerals of FIG. 1 with 200" added thereto. The operation of this FIG. 5 installation is similar to the operation of the FIGS. 1 and 2 installation.

While I have shown and described three embodiments in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art, and I therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

lclaim:

1. An installation for venting a crankcase on an internal combustion engine of the type having air inlet means for introducing air to the engine from the atmosphere and exhaust means for exhausting gases from the engine to the atmosphere; said installation comprising exhaust valve means for operatively closing said exhaust means, vent line means connecting said crankcase to said air inlet means for venting crankcase gases thereto, closure valve means for selectively closing said vent line means with respect to the atmosphere, closure valve actuating means for operatively closing said clo sure valve means in response to closing of said exhaust valve means, and storage means for storing air and crankcase gases during the condition when said exhaust valve means and said closure valve means are operatively closed.

2. An installation according to claim 1, characterized in that said closure valve actuating means includes a direct mechanical linkage between said exhaust valve means and said closure valve means.

3. An installation according to claim 2, characterized in that means are provided for closing said exhaust valve means in response to engine braking.

4. An installation according to claim 1, characterized in that said storage means includes an air tank.

5. An installation according to claim 4, characterized in that said air tank means is operatively connected to the vent line means at a position between the crankcase and the closure valve means.

6. An installation according to claim 5, characterized in that the closure valve means and air tank are arranged in the an inlet means.

7. An installation according to claim 5, characterized in that said closure valve means is a throttle valve in an air suction line of the en ine. a

8. An insta ation according to claim 5, characterized in that a pipe connection in communication with the atmosphere is connected to the vent line means in parallel to the crankcase and in that a pressure limit valve is arranged in the pipe connection.

9. An installation according to claim 8, characterized in that the closure valve means and air tank are arranged in an air suction line of the engine.

10. An installation according to claim 8, characterized in that suction pump is arranged in the vent line means.

11. An installation according to claim 8, characterized in that an air filter is arranged in the pipe connection for the atmospheric air.

12. An installation according to claim 11, characterized in that the discharge end of the vent line means terminates downstream of a suction air filter in the air inlet means.

13. An installation according to claim 4, characterized in that a pipe connection in communication with the atmosphere is connected to the vent line means in parallel to the crankcase and in that a pressure limit valve is arranged in the pipe connection.

14. An installation according to claim 13, characterized in that an air filter is arranged in the pipe connection for the atmospheric air.

15. An installation according to claim 4, characterized in that said closure valve means is a three-way valve in the vent line means.

16. An installation according to claim 15, characterized in that said three-way valve includes means for connecting said vent line means directly to said air inlet means when said exhaust valve means is open and means for connecting said vent line means directly to said air tank when said exhaust valve is closed.

17. An installation according to claim 16, characterized in that pump means are provided between said crankcase and said three-way valve for pumping the crankcase gases.

18. An installation according to claim 4, characterized in that the discharge end of the vent line means terminates in a suction air line upstream of a suction air filter.

19. An installation according to claim 4, characterized in that a suction pump is arranged in the vent line means.

20. An installation according to claim 4, characterized in that the discharge end of the vent line means terminates in the suction air line upstream of a air inlet means.

21. An installation according to claim 4, characterized in that the discharge end of the vent line means terminates downstream of the inlet means filter in the air suction line. 

1. An installation for venting a crankcase on an internal combustion engine of the type having air inlet means for introducing air to the engine from the atmosphere and exhaust means for exhausting gases from the engine to the atmosphere; said installation comprising exhaust valve means for operatively closing said exhaust means, vent line means connecting said crankcase to said air inlet means for venting crankcase gases thereto, closure valve means for selectively closing said vent line means with respect to the atmosphere, closure valve actuating means for operatively closing said closure valve means in response to closing of said exhaust valve means, and storage means for storing air and crankcase gases during the condition when said exhaust valve means and said closure valve means are operatively closed.
 2. An installation according to claim 1, characterized in that said closure valve actuating means includes a direcT mechanical linkage between said exhaust valve means and said closure valve means.
 3. An installation according to claim 2, characterized in that means are provided for closing said exhaust valve means in response to engine braking.
 4. An installation according to claim 1, characterized in that said storage means includes an air tank.
 5. An installation according to claim 4, characterized in that said air tank means is operatively connected to the vent line means at a position between the crankcase and the closure valve means.
 6. An installation according to claim 5, characterized in that the closure valve means and air tank are arranged in the an inlet means.
 7. An installation according to claim 5, characterized in that said closure valve means is a throttle valve in an air suction line of the engine.
 8. An installation according to claim 5, characterized in that a pipe connection in communication with the atmosphere is connected to the vent line means in parallel to the crankcase and in that a pressure limit valve is arranged in the pipe connection.
 9. An installation according to claim 8, characterized in that the closure valve means and air tank are arranged in an air suction line of the engine.
 10. An installation according to claim 8, characterized in that suction pump is arranged in the vent line means.
 11. An installation according to claim 8, characterized in that an air filter is arranged in the pipe connection for the atmospheric air.
 12. An installation according to claim 11, characterized in that the discharge end of the vent line means terminates downstream of a suction air filter in the air inlet means.
 13. An installation according to claim 4, characterized in that a pipe connection in communication with the atmosphere is connected to the vent line means in parallel to the crankcase and in that a pressure limit valve is arranged in the pipe connection.
 14. An installation according to claim 13, characterized in that an air filter is arranged in the pipe connection for the atmospheric air.
 15. An installation according to claim 4, characterized in that said closure valve means is a three-way valve in the vent line means.
 16. An installation according to claim 15, characterized in that said three-way valve includes means for connecting said vent line means directly to said air inlet means when said exhaust valve means is open and means for connecting said vent line means directly to said air tank when said exhaust valve is closed.
 17. An installation according to claim 16, characterized in that pump means are provided between said crankcase and said three-way valve for pumping the crankcase gases.
 18. An installation according to claim 4, characterized in that the discharge end of the vent line means terminates in a suction air line upstream of a suction air filter.
 19. An installation according to claim 4, characterized in that a suction pump is arranged in the vent line means.
 20. An installation according to claim 4, characterized in that the discharge end of the vent line means terminates in the suction air line upstream of a air inlet means.
 21. An installation according to claim 4, characterized in that the discharge end of the vent line means terminates downstream of the inlet means filter in the air suction line. 